In another work, they conjugated a purine-containing derivative which was discovered as a highly potent EGFR-TKI with lenalidomide and VHL ligand to obtained a PROTAC library.55 The most potent degrader 28 (P3, Fig. 7) effectively induced the degradation of mutant EGFR with a DC50 of 0.51 nM, Dmax of 80.4% and DC50 of 126 nM, Dmax of 90.3% in HCC-827 (EGFRe19d) cells and H1975 (EGFRL858R/T790M) cells, respectively. This evidence concerns the gene EGFR and hepatocellular carcinoma.